No way to troubleshoot no dial tone

If you ask XA for help troubleshooting no dial tone, you get this:

To fix no dial tone with your Xfinity Voice service,
      1. First ensure all phones are on the hook and cordless phone batteries are charged.
      2. Try plugging a working corded phone into different jacks to isolate the issue.
      3. If the problem persists, plug the phone directly into your Xfinity Voice modem to check for wiring issues.

I have done these things and they haven't worked. But the options are "This fixed my issue" and "More Troubleshooting Help". More help routes you back to this.

There is no option for "This didn't fix my issue" or additional support. So I've paid for phone and I have no phone and no way to get a dial tone, just an ever-looping Kafkaesque chat that I guess provides some legal definition of "support" without actually providing support -- or, for that matter the product I purchased.